Answer:
A.
Step-by-step explanation:
A sound argument can be defined as those arguments whose all premises are true and thus valid.
The given statement is an example of a deductive argument. A deductive argument is those arguments that start with developing a factual premise to reach a valid conclusion. A valid argument whose premises are true will be considered a sound argument.
The given argument is valid as the facts presented "Every homeroom in our school has more girls than boys..." reaches a valid conclusion "so there are more girls than boys in our school."
Thus, this argument is sound.